Laminated Sheet Material And Methods Of Making Such Material are disclosed in U.S. Pat. No. 3,530,023 which issued Sept. 22, 1970 to R. W. Schutte et al. As disclosed, such material comprises at least two adjacent layers of cellulosic fiber sheet material, and a layer of thermoplastic material which layers are secured together at a plurality of bonding areas by heat and pressure without the addition of any adhesive material. This patent states that such bonding may be achieved by forwarding the layers through a nip between two rolls which rolls are arranged to maintain a fixed spacial relationship relative to each other. As further disclosed, one of the rolls may be smooth surfaced with the other having spaced projections extending outwardly from its cylindrical surface; or both rolls may have such projections. Bonding areas of a size of from about 0.0005 to about 0.002 square inches (from about 0.003 to about 0.013 square centimeters) are said to be preferred.
A non-woven structure, method and apparatus for producing non-wovens is disclosed in U.S. Pat. No. 4,035,219 which issued July 12, 1977 To David Charles Cumbers. In this apparatus as disclosed, a thermoplastic non-woven is first formed as by extruding the thermoplastic from a spinneret; and then passing the filamentary mass through bonding means. In the bonding means, a bonding member such as a roll is provided which has projections on it; the bonding member is heated to a temperature below the softening point of the thermoplastic to be bonded, and the bonding member is pressure biased towards a backing member such as a roll; and the material to be bonded is passed therebetween. For example, through the nip between a pair of pressure biased nip rollers: a heated pattern roller having projections; and a backing roller. Bonding is said to be effected by virtue of the work done by the pressure biased, heated projections to compress the material. Projections having areas of from about 0.00001 to about 0.005 square inches (from about 0.00006 to about 0.003 square centimeters) are stated to be preferred albeit projections having areas of up to about 0.001 square inches (about 0.006 square centimeters) are claimed.
While prior art laminating apparatuses and methods for laminating web materials together have addressed some of the problems of achieving such lamination in the absence of adhesives, they have not addressed the problems to the extent of or in the manner of the present invention. For example, and without intending to thereby limit the scope of the present invention, providing an apparatus wherein laminating is achieved through the use of pressure biased laminating rolls which are operated with a predetermined surface velocity differential between them as provided by one aspect of the present invention; and providing an apparatus having heated, velocity method laminating members having pattern elements having areas of greater than 0.002 square inches (about 0.013 square centimeters) which apparatus is particularly useful at intermediate and high line velocities as is provided by another aspect of the present invention.